The invention relates to a cross member system for a coupling device of a motor vehicle including a tubular cross member which extends between two lateral fastening consoles, and a coupling mounting connected to the cross member in a central section of the cross member.
U.S. Pat. No. 4,032,170 A discloses an assembly of parts and a method for welding these parts together in order to provide a trailer coupling for motor vehicles. The components of the coupling can be welded together in different configurations so as to be adjustable to different vehicle types such as passenger car, station wagons, Pickup trucks or small buses. The focus in this context is on the North American market. One feature is the trailer coupling or the coupling hook which can be welded in a central tubular coupling mounting. A further feature are the two lateral fastening consoles. These are formed by two tubular legs which are welded at an angle to each other. One of the legs is arranged in the cross member so as to be longitudinally shiftable and fixable in the cross member. The other leg, which is oriented in longitudinal direction of the vehicle, is associated to a longitudinal member of the vehicle frame and movable relative to the longitudinal member and is fixable to the longitudinal member.
EP 1 008 468 B2 discloses a coupling carrier for motor vehicles including a cross member on which a trailer coupling can be mounted. Two holders, which are spaced apart in longitudinal direction of the cross member, carry the cross member. The holders can be connected to mounting sites provided on a body of the motor vehicle. The cross member is connected with the holders by means of connecting elements in the form of intermediate parts extending between the cross member and the holders.
DE 101 07 080 A1 describes a trailer coupling for a motor vehicle with a cross member which can be fastened to vehicle support members via mountings. On the cross member a coupling device is fastened.
The conventional construction of a cross member system common in the state of the art includes a tubular cross member extending between two lateral fastening consoles and a coupling mounting which is connected with the cross member in a central section of the cross member. This construction is shown in FIG. 1.
The cross member is formed by a welded tube or a seamlessly extruded tube and has either a rectangular or square or circular cross section continuous along its entire length. Usually the cross member has a wall thickness of 5 mm to 7 mm and is made of a steel with a tensile strength of 300 MPa to 400 MPa. With a weight of 25 kg to 30 kg the cross member is relatively heavy and correspondingly also the entire cross member system.